Field of the Invention
Embodiments of the present disclosure generally relate to power conversion and, more particularly, to a method and apparatus for determining local phase connections in a multi-phase power line system.
Description of the Related Art
DC-AC inverters convert DC current received from a DC source, such as a renewable energy source, to AC current. One option to use the energy produced is to couple the generated AC current to an AC system such as the commercial power grid.
For inverters that generate one or two phases of AC power and are coupled to a three-phase commercial power grid, the same number (or roughly the same number for large enough systems) of inverters must be coupled to each unique subset of phase lines in the three-phase system in order to produce a balanced three-phase output from the inverters. In order to meet certain relevant safety requirements and/or to implement various features for Advanced Grid Functions (AGF), changes or faults occurring on only one of the three phases may require adjustments by the inverters coupled to one or more of the remaining phases. However, in such a system each inverter only has visibility to those phases to which it is connected; any events occurring on only a single phase line will not be observed by those inverters that are not connected to that phase line.
Therefore, there is a need in the art for a method and apparatus for efficiently determining local phase connections in a multi-phase system.